What causes breakouts?

STRESS
When we're stressed, our bodies release corticotrophin releasing hormone. CRH triggers the release of inflammatory cytokines and promotes the production of oil. Excess oil can clog pores and when combined with inflammation, lead to breakouts. Take a breather, go for a walk or listen to calming sounds to relax you.
Acne Treatments
Going overboard on acne-fighting products can lead to skin irritation, inflammation, and dry skin. Overly dry skin will react by producing more oil and that oil can clog pores. Ease up on the acne treatments.
Smoking
Several studies suggest that smoking contributes to acne. A study in 2009 found that 82% of those with severe acne smoked.
Medications
Drugs that contain androgens, corticosteroid, or lithium can make acne worse so consult your dermatologist if this is happening to you.
Skincare Products
The lotions and creams your using may be to blame for your breakouts. Oil based makeup, some silicones, and some liquid foundations clog pores. Use noncomedogenic products, which don't clog pores.
Over Moisturizing
I get it, you want to make sure your skin is well hydrated but you could be over doing it. When you apply too much moisturizer to your skin it can clog your pores, which can lead to you breaking out. Applying just a dime size amount is good for any skin type.